Deep switch question

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Max
Posts: 1573
Joined: Wed May 31, 2006 6:08 pm

Re: Deep switch question

Post by Max »

jam-mill wrote:Also, isn't 'down' the engaged or 'on' position for the bright cap? If so, seems like the 'deep' should operate similarly.
1. All the switches of all the original Dumble amps I know are "active" ("active" = deep "on", bright "on", etc.) if the "handle" for manipulating the switch rests in the position nearest to the label

2. AFAIK the influence of an original (unmodified) deep switch in its "deep on" position on the perceived tone of an original Dumble amp is always achieved by a similar kind of circuit

3. When looking into an unmounted chassis of an original Dumble amp with a deep switch, the orientation of the wiring you'll see depends on
  • a) the type of switch
    b) the position of the label depending on how the chassis is mounted in its cabinet (hanging under the top of its cabinet or standing on the bottom of its cabinet)
Example:

Concerning the circuit of the deep switch in ODS #0094 this schematic has been proposed by ic-racer: http://ampgarage.com/forum/download/file.php?id=37828

Concerning the look of the wiring of the deep switch in ODS #0094 this picture has been posted by Charlie Wilson: http://ampgarage.com/forum/download/file.php?id=37804

Concerning the position of the "DEEP" label on the front panel of ODS #0094 I've attached a picture (source: http://www.roblivesey.com/dumble/)

For a comparison I've attached a picture of the wiring in the 2nd generation ODS #0040 with a slide switch for the "deep" function and a picture of the position of the "DEEP" label on the front panel of this ODS #0040 (source: http://www.roblivesey.com/dumble/). And here's the layout for a 2nd generation ODS with slide switches posted by talbany in the "Dumble Files" section : http://ampgarage.com/forum/download/file.php?id=24300

Cheers,

Max
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jam-mill
Posts: 222
Joined: Sun Nov 17, 2013 8:37 pm
Location: San Diego, CA

Re: Deep switch question

Post by jam-mill »

Max wrote:
jam-mill wrote:Also, isn't 'down' the engaged or 'on' position for the bright cap? If so, seems like the 'deep' should operate similarly.
1. All the switches of all the original Dumble amps I know are "active" ("active" = deep "on", bright "on", etc.) if the "handle" for manipulating the switch rests in the position nearest to the label

[...]

Cheers,

Max
Max,
Thank-You for providing the additional detail.

Is there an instance of a Dumble amplifier with a 'bright' switch that allows selection of one of two different bright caps, or no bright cap (SPDT or DPDT on-off-on switch)? If so, how was the front panel labeled?

Also, regarding switch labeling, aren't there instances of Dumble amplifiers with a DPDT on-off(on?)-on for the 'rock/jazz' switch where the 'center' position is neither 'rock' nor 'jazz', but tone stack bypass? Are there instances where this switch center position is actually labeled?

Regards,
-jack
RCGPNY1
Posts: 180
Joined: Fri Jan 03, 2014 4:56 pm
Location: TENNESSEE

Re: Deep switch question

Post by RCGPNY1 »

Just for adding my 2 cents...the deep switch on Dumble-style amp is
just like the Deep switch on a blackface Fender Bassman head. I play guitar, but I always used the Bass channel of blackface Bassmans with the deep switch "on", treble on 10 and bass "0". It always seemed less "deep" in the "deep" position. What I assumed was going 0n was that a mid-bass peak was actually removed with the deep switch on, effectively
making the response seem more linear into the low range:less mid bass =more apparent low bass.
Max
Posts: 1573
Joined: Wed May 31, 2006 6:08 pm

Re: Deep switch question

Post by Max »

jam-mill wrote:Is there an instance of a Dumble amplifier with a 'bright' switch that allows selection of one of two different bright caps, or no bright cap (SPDT or DPDT on-off-on switch)?
Up to now I never met such a bright switch. But as I'm familiar with only less than 10% of all the amps built by Alexander Dumble, of course it's possible that such an amp exists.
jam-mill wrote:Also, regarding switch labeling, aren't there instances of Dumble amplifiers with a DPDT on-off(on?)-on for the 'rock/jazz' switch where the 'center' position is neither 'rock' nor 'jazz', but tone stack bypass?
Yes, some R/J switches provide a preamp boost function in a center position.
jam-mill wrote:Are there instances where this switch center position is actually labeled?
Yes, the center position of some of the R/J switches with a preamp boost function is labeled "PB". I've attached a picture (source: http://www.roblivesey.com/dumble/)

Cheers,

Max
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jam-mill
Posts: 222
Joined: Sun Nov 17, 2013 8:37 pm
Location: San Diego, CA

Re: Deep switch question

Post by jam-mill »

Max wrote:
jam-mill wrote:Is there an instance of a Dumble amplifier with a 'bright' switch that allows selection of one of two different bright caps, or no bright cap (SPDT or DPDT on-off-on switch)?
Up to now I never met such a bright switch. But as I'm familiar with only less than 10% of all the amps built by Alexander Dumble, of course it's possible that such an amp exists.
jam-mill wrote:Also, regarding switch labeling, aren't there instances of Dumble amplifiers with a DPDT on-off(on?)-on for the 'rock/jazz' switch where the 'center' position is neither 'rock' nor 'jazz', but tone stack bypass?
Yes, some R/J switches provide a preamp boost function in a center position.
jam-mill wrote:Are there instances where this switch center position is actually labeled?
Yes, the center position of some of the R/J switches with a preamp boost function is labeled "PB". I've attached a picture (source: http://www.roblivesey.com/dumble/)

Cheers,

Max
Max,

Forgot to say thank-you for sharing a wealth of information; always very helpful! Also, wanted to let you know that I purchased the Elgam Collective recording based on the example clips posted elsewhere. That sure is a talented group of people. The compositions are interesting and the musicianship is top notch!

Kindest Regards,
-jack
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